What is the major side effect of opioid analgesics?

The major side effect of opioid analgesics is respiratory depression, which is a critical concern in clinical practice. Opioids work by binding to specific receptors in the brain and spinal cord, which modulate pain perception but also depress the central nervous system's function. This depression can lead to decreased respiratory rate and depth, which is particularly dangerous in scenarios where the patient may already have compromised respiratory function or is receiving high doses of opioids.

Monitoring respiratory status is paramount when administering these medications, as severe respiratory depression can lead to hypoxia, brain injury, or even death. While nausea, constipation, and drowsiness are common side effects of opioids, respiratory depression poses the most urgent risk to patient safety. Hence, it is essential for healthcare professionals to be vigilant and prepared to intervene if a patient exhibits signs of respiratory depression after opioid administration.